hwdb: say that settings can be also set to 0

We recommend that users create overriddes. This creates the problem that there
is no syntax to unset a property. Thus, the user needs to just set the property
to "something else" in the override file. But then the blurb saying that
"VAR=1" (or "VAR=0" in some cases) is the only allowed value can be confusing.
Say that both 0 and 1 can be set, since this documentation is also intended
for end users.

In our files, we generally don't want the override values anywhere. But we
have a test which checks the rvalue, which should be enough.

hwdb.d/60-autosuspend.hwdb

@@ -22,9 +22,9 @@
 # for the device.
 #
 # Allowed properties are:
-#    ID_AUTOSUSPEND=1
+#    ID_AUTOSUSPEND=0|1
 #    ID_AUTOSUSPEND_DELAY_MS=####
-#    ID_PERSIST=0
+#    ID_PERSIST=0|1
 #
 # ID_AUTOSUSPEND_DELAY_MS adjusts the delay for autosuspend to something
 # different than the kernel default of 2000ms.

hwdb.d/60-seat.hwdb

@@ -8,7 +8,7 @@
 # device, and not the (parent) PCI device, is tagged with 'master-of-seat'.
 #
 # Allowed properties are:
-#    ID_TAG_MASTER_OF_SEAT=1
+#    ID_TAG_MASTER_OF_SEAT=0|1
 
 #########################################
 # eXtreme Graphic Innovation (XGI)

hwdb.d/70-av-production.hwdb

@@ -21,7 +21,7 @@
 # for the device.
 #
 # Allowed properties are:
-#   ID_AV_PRODUCTION_CONTROLLER=1
+#   ID_AV_PRODUCTION_CONTROLLER=0|1
 
 ################
 # Ableton

hwdb.d/70-hardware-wallets.hwdb

@@ -18,7 +18,7 @@
 # for the device.
 #
 # Allowed properties are:
-#   ID_HARDWARE_WALLET=1
+#   ID_HARDWARE_WALLET=0|1
 
 ################
 # Trezor Hardware Wallets

hwdb.d/70-lights.hwdb

@@ -20,7 +20,7 @@
 # for the device.
 #
 # Allowed properties are:
-#   ID_AV_LIGHTS=1
+#   ID_AV_LIGHTS=0|1
 
 ################
 # Logitech

hwdb.d/70-software-radio.hwdb

@@ -19,7 +19,7 @@
 # for the device.
 #
 # Allowed properties are:
-#   ID_SOFTWARE_RADIO=1
+#   ID_SOFTWARE_RADIO=0|1
 
 ################
 # Nuand